66 Silicon chip Australia’s electronics magazine siliconchip.com.au
brightly, indicating that the unit was
now working. I turned it off and dis-
connected the plugpack and replaced
the 12 screws that secure the unit to-
gether, as well as refitting the stand. I
could now return the unit to use again
after a successful repair.
My wife and I both noticed that the
display was now a much better col-
our than it had been previously. I con-
cluded that as the old capacitor was
failing, that the voltage for the back-
lighting must have dropped, therefore
resulting in a duller than normal back-
light and therefore a slightly washed-
out picture.
The replacement cost of a brand new
unit equivalent to this one is over $100,
so for 45 cents and a bit of time, this
unit was saved from the scrap heap and
will live on in its second life.A Suzuki Vitara and its
discharging battery
S. Z., of Queanbeyan, NSW had the
maddening experience of not being
able to track down the source of an in-
termittent fault. Most of us know what
that’s like; it seems that the problem
will occur any time except for when
you are trying to track down its cause!
He found it in the end, although it took
a great deal of luck...
After a long period of being very
kind to batteries (some lasting many,
many years), my Suzuki Vitara re-
cently started killing them. It began
on the morning of the Australia Day
long weekend. We were about to leave
for a big trip to Morton National Park
to tackle Monkey Gum Fire Tail when
the car refused to start. The battery
was dead flat. That’s never happened
before.
At the time, I surmised it was justthe inverter board has a plastic cover
over it, I couldn’t mount the replace-
ment vertically.
With a new capacitor fitted, I re-
installed the inverter board and went
to re-connect the four plugs that I had
disconnected earlier. But when I went
to re-connect the 20-pin plug on the
video board, but I ran into a problem.
Typically, there is one pin missing
on the header and a blank in the plug,
so you can’t insert it backwards, but
in this case, there was not and I had
not paid any attention to the orienta-
tion of the plug when I’d removed it.
Being mindful that if I put the plug on
the wrong way, I could damage some-
thing, I had a closer look at the PCB
and the plug.
Luckily, on closer inspection, it was
obvious which way the plug went on.
The PCB was marked +3.3V at one end
of the header, and the 20-pin plug had
two red wires at one end. The other
end had two holes with no wires in
them. So clearly, the end of the plug
with the two red wires went to the end
of the header that was marked +3.3V
on the PCB.
Because of the missing wires, it
seems that no damage would have
occurred if it was reversed anyway, it
just wouldn’t have worked.
Before permanently attaching the
back, I gave the unit a quick test to
make sure that it was working. On
connecting it up and turning on the
switch, I could see the splash screen
very faintly, indicating that the back-
lighting was not operating. I then real-
ised that one of the plugs for the back-
lighting that I had just re-connected
had come out, so I plugged it back in
and tried again.
This time, the screen came upA few years ago, we bought a
used 15-inch digital photo frame on
Gumtree. Initially, I had some prob-
lems setting up this unit, as it didn’t
want to display the photos on the SD
card and reverted to showing the stock
photos on the inbuilt memory.
I solved this by deleting the stock
photos and putting our photos on the
inbuilt memory. It then performed well
for a few years.
But recently, my wife commented
that she was having problems getting
the photos to display and she would
need to power the unit on and off sev-
eral times before it started working.
This went on for around a week; then
it just stopped working altogether.
I observed that it would initially
show the splash screen for around
one second, then a blank screen. I
tried a different plugpack power sup-
ply in case that was faulty, but noth-
ing changed.
So the unit itself was faulty and I
suspected that it might be a dud ca-
pacitor. I started opening it up by re-
moving the 12 #1 Philips head screws
from the back cover, which gave ac-
cess to the inside. I then disconnect-
ed four plugs so I could remove the
back completely and inspect the cir-
cuit boards.
It didn’t take long to spot the faulty
electrolytic capacitor on the invert-
er board. The bung had been pushed
out the bottom of the 220μF 25V unit.
That was apparently the problem, and
I thought it would be an easy fix.
Usually, I would use a salvaged ca-
pacitor for repairs like this, but be-
cause this capacitor was lying down,
I would need to use a new capacitor
with long leads. Because of the limited
space inside the unit and the fact that